The present invention relates generally to a novel construction for a synchronous/asynchronous exercise machine, such as a ski exercise machine and the like. More specifically, the invention relates to a novel quick change mechanism for changing a synchronous/asynchronous exercise machine, such as a ski exercise machine and the like, between a synchronous exercise mode and an asynchronous exercise mode.
Many people these days desire to get in shape and stay physically fit. By getting in shape and staying physically fit, people may be able to improve their health and quality of life. To provide a method by which this desire may be fulfilled, a number of firms have developed and market pieces of exercise equipment. These pieces of exercise equipment may have different constructions depending upon the type of workout provided. For instance, there are exercise cycles, rowing machines, step walkers, free weight assemblies, butterfly exercisers, and the like. Generally, each of these pieces of exercise equipment is designed to exercise a certain portion or muscle group of the human body. For example, exercise cycles may primarily exercise the leg muscles, while butterfly exercisers may primarily work on the arm muscles.
However, there are some pieces of exercise equipment which can exercise more than one muscle group at a given time. One such piece of exercise equipment is a ski exercise machine. Ski exercise machines may allow a user to exercise the leg muscles and the arm muscles, and may also provide a way for exercising the shoulder and abdominal muscles. Thus, a user working out on a ski exercise machine may be able to reduce the amount of time spent working out because a number of muscle groups can be exercised at the same time. Accordingly, ski exercise machines have become quite popular.
Ski exercise machines in general provide mechanisms for mechanically mimicking the actions and/or body movements associated with cross country skiing. In general, them are two types of machines. In one type, the ski exercise machine requires the user to reciprocate his legs in a synchronized scissor-like manner. For example, as the fight leg moves forward, the left leg moves backward. Synchronization is typically provided by attaching foot supports or slides to opposite sides of a continuous loop, so that forward movement of one slide results in simultaneous rearward movement of the other slide. This regular, opposite reciprocating motion is defined, for the purposes of this disclosure, as the synchronous or novice exercise mode. This exercise mode may be recommended for a beginner starting to ski or exercise with a ski exercise machine.
In cross country skiing, however, more experienced skiers may not always oppositely reciprocate their legs, but may, at times, move their legs forward or backward independently. Thus, in a second type of ski exercise machine, the foot slides are free to move independently of each other. This independent movement is defined, for the purposes of this disclosure, as the asynchronous or expert exercise mode. Although the asynchronous mode of skiing exercise movement may be relatively difficult for a user to learn, especially for a beginner who is just learning to use a ski exercise machine, it more accurately mimics actual cross country skiing.
A few illustrative examples of machines which may be similar in some respects to the above-discussed ski exercise machines are disclosed in the following United States Patents.
______________________________________ Rodgers 4,679,786 07/14/87 Rodgers, Jr. 4,900,013 02/13/90 Rogers, Jr. 5,131,895 07/21/92 ______________________________________
While these exercise machines and apparatuses may perform well in some circumstances, and may be relatively easy for some people to use, these apparatuses do have some characteristics which may make them undesirable to some people. Specifically, the construction of these exercise apparatuses may make it difficult for a beginner to learn the proper ski exercise movements, i,e. the novice and expert exercise modes discussed above, and may also lead to an inefficient workout.
The exercise apparatuses disclosed in the above-referenced patents generally comprise a number of traveller brackets or slides for accepting forces applied by a user's legs and/or arms. Responsive to the forces applied by the exercising user, the slides travel along tracks mounted on a main frame of the exercise apparatus. In order to provide resistance to movement of the slides, a load source, against which the user can exercise, may be operatively connected to the slides, such as by a drive chain, a drive belt, or similar structure. The degree of resistance provided by the load source may be varied by appropriate methods well known to those skilled in the art. The slides may be connected to the drive chain so that as one slide moves forward, another slide moves backward. This motion may, in some circumstances, be similar to the movements associated with the above-discussed novice mode of cross country skiing. However, these exercise apparatuses may not be able to provide a user with an effective workout as the user increases his skill and strength, and may not be able to generally provide the expert exercise mode.
In order for a user to develop his body and to have an effective workout, it is desirable that each exercised limb, e.g. a leg, work against a controlled resistance. Such resistance is typically provided in one direction only, such as when pushing back with a leg, for example. This one direction is commonly referred to as a power stroke. Also, it may be desirable for the user, once he has developed sufficient skill with the movements to be performed on the exercise apparatus, to change from working out in the novice exercise mode and to begin working out in the expert exercise mode, during which the user moves each of his legs independently of each other with each leg provided with an independent power stroke.
The exercise apparatuses of the above-referenced prior art patents may not easily adapt to these changes required by the exercising user. For instance, the exercise apparatus of the '895 patent has a single drive chain to which two slides are attached. These two slides are to be driven forward and backward by the user's feet. The drive chain is, in turn, operatively connected to a brake for providing resistance to movement of the drive chain, and thus, of the slides. The single drive chain may cause the slides to relatively reciprocate similar to the novice exercise mode discussed earlier. However, as the user increases his skill, he may wish to change to the expert mode. This exercise apparatus does not allow a user to do this.
The exercise machine disclosed in the '786 patent utilizes a number of slides which may be connected to a single drive chain, or, alternatively, may be each connected to its own drive chain. The drive chain is connected to a flywheel, which provides the load, through an overrunning or one way clutch. In this manner, as the drive chain, and the connected slides, move in a predetermined driving direction, the user must work against the load provided by the flywheel to move the slides in that predetermined direction (power stroke). The clutches allow the drive chain and the slides to move freely, independent of the flywheel, in a direction opposite to the predetermined direction, and the power stroke is executed only in the predetermined direction.
The slides are connected to the drive chain by a mechanism which allows a user to change the predetermined direction of the power stroke. Therefore, at the user's option, either the forward or the rearward direction of movement of the slides may correspond to the direction of the power stroke. In this machine, the slides may also be selectively disconnected from the drive chain. Disconnection of a slide from the drive chain presents a number of drawbacks which may make that procedure, and the exercise machine in general, unattractive to a user. Specifically, by disconnecting a slide from the drive chain, the slide is also disconnected from the flywheel. The resistance against which the user needs to exercise is removed from that slide. Thus, the foot on that slide does not encounter any resistance to its movement. This can lead to an inefficient workout because the disconnected slide essentially moves freely along its associated track. Because one slide is connected to the drive chain and another is disconnected from the drive chain, the workout is unbalanced. In addition, it may be difficult to disconnect a slide from the drive chain, and further difficulties may be encountered when the user attempts to reconnect the slide to the drive chain.
The exercise apparatus disclosed in the '013 patent referenced earlier provides two slides for accepting a user's feet. Each of the slides is individually operatively connected to the flywheel by a separate drive chain. Ends of each of the drive chains, opposite to the ends thereof connected to the flywheel, are connected to a geared transmission mechanism. This transmission includes a number of gears which interact so that the slides may reciprocate in opposite directions. This may produce the motion of the novice exercise mode discussed earlier. By operating the transmission, the gears thereof can be operatively disconnected. The drive chains can then move independently, thereby possibly providing the motions of the expert exercise mode. While the transmission may allow a user to perform both the novice exercise mode and the expert exercise mode on the same exercise apparatus, the transmission mechanism is complexly constructed and expensive. A shifting mechanism of sorts must be provided for operating the transmission and thereby changing the exercise apparatus from the novice exercise mode to the expert exercise mode, and back again. The gears of the transmission may fail or become stripped if not properly positioned. The transmission comprises additional parts of the exercise apparatus which may break or wear out over time. Also, the construction of the shifting mechanism may make it difficult to change between the modes of exercise, and thus, changing between the exercise modes may take considerable time. These disadvantages, among others, may make the exercise machines and apparatuses of the above-referenced patents undesirable to some people.
Accordingly, it is desirable to provide an exercise machine, such as a ski exercise machine and the like, which is not subject to the above-discussed drawbacks. The present invention is intended to provide such an exercise machine.